Various surgical procedures are performed using percutaneous entry into a blood vessel. To facilitate cardiovascular procedures, a small gauge needle is introduced through the skin and into a target blood vessel, often the femoral artery The needle forms a puncture through the blood vessel wall at the distal end of an incision tract that extends through the overlying tissue. A guidewire is then introduced through the bore of the needle, and the needle is withdrawn over the guidewire For procedures requiring the use of a larger cannula, one or more dilators may be passed over the guidewire to expand the tissue opening to larger sizes. When the tissue opening is the appropriate size, an introducer sheath is advanced over the guidewire and the dilator may be removed. The sheath and guidewire are left in place to provide access during subsequent procedures.
The sheath facilitates passage of a variety of diagnostic and therapeutic instruments and devices into the vessel and its tributaries. Illustrative diagnostic procedures include angiography, intravascular ultrasonic imaging, and the like. Exemplary interventional procedures include angioplasty, atherectomy, stent and graph placement, embolization, and the like. After the selected procedure is completed, the catheters, guidewire, and introducer sheath are removed, and it is necessary to close the vascular puncture to provide hemostasis to allow healing.
Traditional methods of achieving hemostasis include the application of external pressure to the skin entry site by a nurse or physician to stem bleeding from the wound until clotting and tissue rebuilding have sealed the perforation. In some situations, this pressure must be maintained for half an hour to an hour or more, during which the patient is uncomfortably immobilized, often with sandbags and the like. With externally applied manual pressure, both patient comfort and practitioner efficiency are impaired. Additionally, a risk of hematoma exists since bleeding from the vessel may continue until sufficient clotting effects hemostasis. Also, external pressure devices such as femoral compression systems, may be unsuitable for patients with substantial amounts of subcutaneous adipose tissue since the skin surface may be a considerable distance from the vascular puncture site, by rendering skin compression inaccurate and thus less effective. Moreover, the application of excessive pressure can occlude the underlying artery, resulting in ischemia and/or thrombosis inside the vessel.
Even after hemostasis has apparently been achieved, the patient must remain immobile and under observation for hours to prevent dislodgement of the clot and to assure that bleeding from the puncture wound does not resume. Renewed bleeding through the tissue tract is not uncommon and can result in hematoma, pseudoaneurisms, and arteriovenous fistulas. Such complications may require blood transfusion, surgical intervention, or other corrective procedures. The risk of these complications increases with the use of larger sheath sizes, which are frequently necessary interventional procedures, and when the patient is anticoagulated with heparin or other drugs.
Various procedures have been used to promote hemostasis without relying on skin surface pressure. Some of these proposals use intraluminal plugs and are characterized by the placement of an object within the blood stream of the vessel to close the puncture. Other proposals include delivery of tissue adhesive to the perforation site. Still further proposed solutions would insert a cylindrical plug into the incision tract that would subsequently expand and seal the puncture site. All of these approaches require either introducing or leaving foreign objects in patient's body and/or inserting a tubular probe of large diameter into the tissue channel left by the catheter in order to seal the puncture.